fix(CI): revert deactivating view during concretization and installation

when deactivating the view, it is deleted, which is problematic in
production deployments

install_spack_env.sh

@@ -96,9 +96,6 @@ cp /tmp/spack.yaml ${CI_SPACK_ROOT}/var/spack/environments/$EBRAINS_SPACK_ENV/
 # activate environment
 spack env activate --without-view $EBRAINS_SPACK_ENV
 
-# deactivate view during concretization and installation
-spack env view disable
-
 spack concretize --force --fresh --test root
 
 # dump dag to file
@@ -147,10 +144,6 @@ fi
 # delay exit code until we have updated the cache below
 spack install --no-check-signature -y -j$SPACK_JOBS --fresh --test root && spack_install_ret=$? || spack_install_ret=$?
 
-# re-enable view
-spack env view enable
-spack env view regenerate
-
 # no need to update the local cache nor the remote cache if we don't want to update
 if [ -n "${OCI_CACHE_PREFIX}" ] && [ "${UPDATE_SPACK_OCI_CACHES:-false}" = "true" ]; then
     # push previously missing (but now installed) packages to the local cache